The present invention refers to a surgical device and method for bone surgery. The device is particularly suitable, for example, for orthopedic surgical procedures such as osteotomy, ostectomy, osteoplasty etc. and for oral surgical procedures such as excision of cysts, third molar extraction, preparation of implant sites, creation of an opening into the maxillary sinus and elevation of the endosteum.
Bone surgery operations that involve cutting of the bony tissue (osteotomy) and/or modeling thereof (osteoplasty) have hitherto been performed with manual and/or rotary instruments. Manual instruments consist of scalpels and/or chisels operated by hand or with a mallet. Rotary instruments consist of motor-driven milling cutters or disks.
These methods both have serious limitations if they have to be used in difficult situations such as restricted surgical access, anatomically difficult bone conditions and particularly when it is necessary to operate in the vicinity of soft tissue.
The cutting characteristics of the techniques currently in use are unsatisfactory for the following reasons:
the cutting depth is poorly controlled;
the mechanical force is often excessive, therefore cutting directionality is lost and/or accidental fractures are caused;
cutting is not selective and can therefore damage the soft tissue (for example the vascular nerve bundles).
The object of the invention is to eliminate these drawbacks by providing a surgical device for bone surgery that makes it possible to perform surgical procedures with the utmost precision and therefore with less risk.
Another object of the present invention is to provide such a surgical device for bone surgery that is practical and versatile.
Another object of the present invention is to provide such a device for bone surgery that is capable of cutting the mineralized bone tissue without causing cuts and lesions in the soft tissue, and particularly in the neurovascular structures.
These objects are achieved according to the invention with the characteristics listed in appended independent claim 1.
Another object of the present invention is to provide a surgical method for bone surgery that is most accurate, efficient and with less risk for the patient.
This object is achieved according to the invention with the characteristics listed in appended independent claim 14.
Preferred embodiments of the invention will be apparent from the dependent claims.
The surgical device for bone surgery according to the invention provides a handpiece comprising a tip capable of operating on bone tissue. For this purpose, according to requirements, various tips such as chisels, compressors, osteotomes, periosteal or endosteal elevators etc. can be mounted on the handpiece.
The handpiece comprises a transducer, which can be piezoceramic, for example, and serves to generate sound waves that set the tip in vibration. The tip is made to vibrate at a frequency within the sonic and ultrasonic range so that when it comes into contact with the mineralized bone tissue an extremely fine and precise cut is made in said tissue. Compression, compaction and displacement of said tissue is also possible according to surgical requirements.
The surgical device according to the invention can be equipped with a console which provides for the electrical and hydraulic supply to the handpiece. The console has a keyboard that can be operated by the operator to control the control electronics of the handpiece.
The control electronics allow the handpiece to be operated with sonic and/or ultrasonic vibrations, modulated or not at low frequency or with low frequency bursts. In this manner the user can modulate the ultrasound pulses to be transmitted to the tip of the handpiece according to the requirements of the surgical procedure.
The surgical device for bone surgery according to the invention has various advantages.
With the surgical device for bone surgery according to the invention, the cutting action on the bone tissue is produced by variable modulation ultrasonic vibrations that are activated only on the cutting end of the tip that comes into contact with the mineralized tissue to be cut. Consequently, the bone tissue surface affected by the action is extremely small. This allows the surgeon to draw the ideal type of procedure that he intends to carry out on the bone tissue with extreme precision. Thus, for example, the actual cut made by the tip will differ minimally from the ideal cut planned beforehand by the surgeon.
Another advantage of the surgical device according to the invention is provided by the fact that, since the cut is extremely fine, the trauma suffered by the bone tissue due to the friction of the cutting instrument and the resulting heat loss will be minimal.
Furthermore, when the vibrating tip encounters soft tissue, such as a neurovascular structure, it loses its cutting capacity. In fact the soft tissue absorbs the vibrations of the tip without being resected and the energy caused by the vibrations of the tip is dissipated in the form of a slight heat. This can be further reduced by the surgeon""s promptness in withdrawing the instrument as soon as he feels that it does not vibrate any more. The transmission of heat into soft tissue, such as neurovascular structures, therefore causes no irreparable damage, as might be that caused by injury or cutting of such structures.
Consequently, if during an operation the surgeon touches a neurovascular structure with the tip, he has plenty of time to withdraw the tip without the problem of causing irreparable damage. Thus use of the surgical device according to the invention makes it possible to solve more severe clinical cases of bone surgery in which it is necessary to operate in the vicinity of neurovascular structures.
For example, the device according to the invention can be used in oral surgery for the following types of operations.
bone sampling in anatomically difficult areas, whether for access or because they are near the nerve endings or where there is extremely little bone tissue;
excision of cysts and/or of inflammatory or phlogistic tissue of the third branch of the trigeminal nerve;
extraction of impacted third molars in the vicinity of the dental alveolus;
preparation of an implant site in the vicinity of nerve endings;
creation of an opening into the maxillary sinus (Caldwell-Luc) without damaging the sinusal membrane;
elevation of the maxillary sinus by the ethmoidal crest route
The device according to the invention can also be used in orthopedic and neurological surgery, in operations such as:
osteoplasty;
ostectomy;
osteotomy in the vicinity of neurovascular structures as is the case, for example, in vertebral surgery.